Cube GUI User Guide  (CubeGUI 4.5-release-preview, revision 18228)
Introduction in Cube GUI and its usage

Communication Efficiency (CommE) is the maximum across all processes of the ratio between useful computation time and total runtime:

CommE = maximum computation time / total runtime

CommE identifies when code is inefficient because it spends a large amount of time communicating rather than performing useful computations. CommE is composed of two additional metrics that reflect two causes of excessive time within communication:

These are measured using Serialisation Efficiency and Transfer Efficiency. In obtaining these two sub-metrics we first calculate (using the Dimemas simulator) how the code would behave if run on an idealised network where transmission of data takes zero time.

These two sub-metrics combine to give Communication Efficiency:

CommE = Serialisation Efficiency * Transfer Efficiency


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